This invention relates to the profile adjustment of a slice lip of a paper machine headbox. In papermaking, the slice opening of a headbox on a paper machine meters flow of the pulp slurry or stock in the headbox onto the fourdrinier wire. A number of axially movable spindles, perhaps 50 to 60, are connected to a headbox control lip or slice lip to vary the metering opening transversely across the machine. The spindles, typically, are threadedly attached at their upper ends to rotationally driven power nuts which linearly drive the individual spindles axially in known manner. The slice lip positional accuracy permits the production control of quality paper by basis weight profiles through the elimination of cross-machine variations.
In adjusting the slice lip, however, care must be taken to have coordinated, gradual adjustments in order to avoid producing "lip kinking" or other force-applied damage to the delicate slice lip. Slice lip protector systems for this purpose are known. One such slice lip protector system permits limited incremental slice lip actuator movement through a series of adjacent slice profiling spindles having mechanically interconnected protectors mounted thereon. The problem with this system, however, is that it permits only first order bend limits which permit a given protector movement up or down a given distance from the position of either of two adjacent mechanically interconnected protectors, one on each side thereof, as will be seen hereinafter.
The system referred to just above is sold by the Black Clawson Paper Machine Group of Watertown, N.Y. 13601 as part of the automatic slice profiling system it sells under the trademark "ESP" II.